Power bank



FIG. 1 is a bottom, front, right perspective view of a power bankshowing our new design;

FIG. 2 is a right side view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a front view thereof, a rear view being a mirror image of thefront view;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

The broken lines depicting portions of the power bank form no part ofthe claimed design.

CLAIM The ornamental design for a power bank, as shown and described.